From: Derrick Stolee Date: Fri, 12 Dec 2025 15:15:28 +0000 (+0000) Subject: scalar: document config settings X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4ce170c522cd91e73e7d500667a4718af125bcf3;p=thirdparty%2Fgit.git scalar: document config settings Add user-facing documentation that justifies the values being set by 'scalar clone', 'scalar register', and 'scalar reconfigure'. Helped-by: Junio C Hamano Helped-by: Patrick Steinhardt Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano --- diff --git a/Documentation/scalar.adoc b/Documentation/scalar.adoc index f81b2832f8..5252fb134a 100644 --- a/Documentation/scalar.adoc +++ b/Documentation/scalar.adoc @@ -197,6 +197,170 @@ delete :: This subcommand lets you delete an existing Scalar enlistment from your local file system, unregistering the repository. +RECOMMENDED CONFIG VALUES +------------------------- + +As part of both `scalar clone` and `scalar register`, certain Git config +values are set to optimize for large repositories or cross-platform support. +These options are updated in new Git versions according to the best known +advice for large repositories, and users can get the latest recommendations +by running `scalar reconfigure [--all]`. + +This section lists justifications for the config values that are set in the +latest version. + +am.keepCR=true:: + This setting is important for cross-platform development across Windows + and non-Windows platforms and keeping carriage return (`\r`) characters + in certain workflows. + +commitGraph.changedPaths=true:: + This setting helps the background maintenance steps that compute the + serialized commit-graph to also store changed-path Bloom filters. This + accelerates file history commands and allows users to automatically + benefit without running a foreground command. + +commitGraph.generationVersion=1:: + While the preferred version is 2 for performance reasons, existing users + that had version 1 by default will need special care in upgrading to + version 2. This is likely to change in the future as the upgrade story + solidifies. + +core.autoCRLF=false:: + This removes the transformation of worktree files to add CRLF line + endings when only LF line endings exist. This is removed for performance + reasons. Repositories that use tools that care about CRLF line endings + should commit the necessary files with those line endings instead. + +core.logAllRefUpdates=true:: + This enables the reflog on all branches. While this is a performance + cost for large repositories, it is frequently an important data source + for users to get out of bad situations or to seek support from experts. + +core.safeCRLF=false:: + Similar to `core.autoCRLF=false`, this disables checks around whether + the CRLF conversion is reversible. This is a performance improvement, + but can be dangerous if `core.autoCRLF` is reenabled by the user. + +credential.https://dev.azure.com.useHttpPath=true:: + This setting enables the `credential.useHttpPath` feature only for web + URLs for Azure DevOps. This is important for users interacting with that + service using multiple organizations and thus multiple credential + tokens. + +feature.experimental=false:: + This disables the "experimental" optimizations grouped under this + feature config. The expectation is that all valuable optimizations are + also set explicitly by Scalar config, and any differences are + intentional. Notable differences include several bitmap-related config + options which are disabled for client-focused Scalar repos. + +feature.manyFiles=false:: + This disables the "many files" optimizations grouped under this feature + config. The expectation is that all valuable optimizations are also set + explicitly by Scalar config, and any differences are intentional. + +fetch.showForcedUpdates=false:: + This disables the check at the end of `git fetch` that notifies the user + if the ref update was a forced update (one where the previous position + is not reachable from the latest position). This check can be very + expensive in large repositories, so is disabled and replaced with an + advice message. Set `advice.fetchShowForcedUpdates=false` to disable + this advice message. + +fetch.unpackLimit=1:: + This setting prevents Git from unpacking packfiles into loose objects + as they are downloaded from the server. The default limit of 100 was + intended as a way to prevent performance issues from too many packfiles, + but Scalar uses background maintenance to group packfiles and cover them + with a multi-pack-index, removing this issue. + +fetch.writeCommitGraph=false:: + This config setting was created to help users automatically update their + commit-graph files as they perform fetches. However, this takes time + from foreground fetches and pulls and Scalar uses background maintenance + for this function instead. + +gc.auto=0:: + This disables automatic garbage collection, since Scalar uses background + maintenance to keep the repository data in good shape. + +gui.GCWarning=false:: + Since Scalar disables garbage collection by setting `gc.auto=0`, the + `git-gui` tool may start to warn about this setting. Disable this + warning as Scalar's background maintenance configuration makes the + warning irrelevant. + +index.skipHash=true:: + Disable computing the hash of the index contents as it is being written. + This assists with performance, especially for large index files. + +index.threads=true:: + This tells Git to automatically detect how many threads it should use + when reading the index due to the default value of `core.preloadIndex`, + which enables parallel index reads. This explicit setting also enables + `index.recordOffsetTable=true` to speed up parallel index reads. + +index.version=4:: + This index version adds compression to the path names, reducing the size + of the index in a significant way for large repos. This is an important + performance boost. + +log.excludeDecoration=refs/prefetch/*:: + Since Scalar enables background maintenance with the `incremental` + strategy, this setting avoids polluting `git log` output with refs + stored by the background prefetch operations. + +merge.renames=true:: + When computing merges in large repos, it is particularly important to + detect renames to maximize the potential for a result that will validate + correctly. Users performing merges locally are more likely to be doing + so because a server-side merge (via pull request or similar) resulted in + conflicts. While this is the default setting, it is set specifically to + override a potential change to `diff.renames` which a user may set for + performance reasons. + +merge.stat=false:: + This disables a diff output after computing a merge. This improves + performance of `git merge` for large repos while reducing noisy output. + +pack.useBitmaps=false:: + This disables the use of `.bitmap` files attached to packfiles. Bitmap + files are optimized for server-side use, not client-side use. Scalar + disables this to avoid some performance issues that can occur if a user + accidentally creates `.bitmap` files. + +pack.usePathWalk=true:: + This enables the `--path-walk` option to `git pack-objects` by default. + This can accelerate the computation and compression of packfiles created + by `git push` and other repack operations. + +receive.autoGC=false:: + Similar to `gc.auto`, this setting is disabled in preference of + background maintenance. + +status.aheadBehind=false:: + This disables the ahead/behind calculation that would normally happen + during a `git status` command. This information is frequently ignored by + users but can be expensive to calculate in large repos that receive + thousands of commits per day. The calculation is replaced with an advice + message that can be disabled by disabling the `advice.statusAheadBehind` + config. + +The following settings are different based on which platform is in use: + +core.untrackedCache=(true|false):: + The untracked cache feature is important for performance benefits on + large repositories, but has demonstrated some bugs on Windows + filesystems. Thus, this is set for other platforms but disabled on + Windows. + +http.sslBackend=schannel:: + On Windows, the `openssl` backend has some issues with certain types of + remote providers and certificate types. Override the default setting to + avoid these common problems. + + SEE ALSO -------- linkgit:git-clone[1], linkgit:git-maintenance[1]. diff --git a/scalar.c b/scalar.c index 3b25fd3f35..21ab1dba89 100644 --- a/scalar.c +++ b/scalar.c @@ -132,6 +132,10 @@ static int have_fsmonitor_support(void) static int set_recommended_config(int reconfigure) { + /* + * Be sure to update Documentation/scalar.adoc if you add, update, + * or remove any of these recommended settings. + */ struct scalar_config config[] = { { "am.keepCR", "true" }, { "commitGraph.changedPaths", "true" },